1. Field of the Invention
This invention relates to a disc drive suspension contained in an information processor, such as a personal computer.
2. Description of the Related Art
A hard disc drive (HDD) for recording and reading information to and from a rotating magnetic disc, magneto-optical disc, etc. has a carriage that can turn around a shaft. A positioning motor turns the carriage around the shaft. The carriage comprises an actuator arm, a suspension on the distal end portion of the arm, a head portion including a slider on the suspension, etc.
When the disc rotates, the slider on the distal end portion of the suspension slightly lifts above the surface of the disc, and an air bearing is formed between the disc and the slider. This suspension comprises a base plate, a load beam, a flexure, etc.
In some cases, a flexure with conductors may be located along the load beam. A magnetic head that includes a slider is mounted on the front end portion of the flexure. The flexure with conductors extends from the load beam toward the base plate.
A disc drive suspension shown in FIG. 6 of Jpn. Pat. Appln. KOKAI Publication No. 2001-155458 comprises a base portion including a base plate, a load beam formed independently of the base portion, and a hinge member that connects the load beam and the base portion. A spring portion (region between the load beam and the base portion) of the hinge member can bend in its thickness direction. The spring constant of the spring portion is an essential factor that determines the properties of the suspension.
If the flexure with conductors is lapped on the hinge member in its thickness direction, as in the case of the suspension described above, the spring constant of the whole spring portion including the flexure with conductors sometimes may be much higher than the sum of the respective spring constants of the simple spring portion and the simple flexure.
The reason is that if the flexure with conductors and the hinge member are fixed overlapping each other, the flexure is pulled in its longitudinal direction when the spring portion bends, so that the spring portion cannot bend with ease. If the spring constant of the suspension increases, it may possibly influence the properties of the suspension.
To solve this problem, a layout may be proposed such that the flexure with conductors detours beside the spring portion. With this arrangement, however, the flexure passes on one side of the spring portion, so that the weight distribution in the region near the spring portion is asymmetric. Besides, that part on which the flexure with conductors is not fixed is so long that the flexure with conductors is liable to swing.
Further, the hinge member may possibly be halved in the width direction of the base portion so that the flexure with conductors can be passed between a pair of hinge members. In general, however, a flexure with conductors is thicker than a hinge member. Owing to a difference in bending radius between the flexure and the hinge member that is caused when the spring portion bends, therefore, the flexure touches the front end of the base portion and the rear end of the load beam. Thus, the flexure with conductors is pulled, so that the spring constant of the spring portion increases.